Thermodynamic pump for cryogenic fueled devices

ABSTRACT

In one embodiment of the disclosure, an apparatus is provided for fueling a device using a cryogenic fluid. The apparatus may comprise: a cryogenic fluid supply container; a vessel connected to the supply container with an entrance valve to regulate flow of cryogenic fluid from the supply container; a heat transfer system capable of transferring heat from a device to the vessel to heat gas in the vessel; and an accumulator connected to the vessel with an exit valve to regulate flow of gas from the vessel to the accumulator. The accumulator may be capable of being connected to a device. In other embodiments, methods are provided of controllably mixing at least one fluid within a fluid mixing device.

REFERENCE TO RELATED APPLICATIONS

The present disclosure is a divisional application of Ser. No.11/750,246, filed on May 17, 2007, the disclosure of which is hereinincorporated by reference in its entirety.

BACKGROUND

There is an interest in using cryogenic fluids such as liquid hydrogen,nitrous oxide, methane, or other fluids as fuel for internal combustionengines, ground vehicles, aircraft, and other devices. In order forcryogenic fluids to be used as fuel for these applications, thecryogenic fluid may need to be supplied to the engine at specificconditions. These conditions may require cryogenic fluid to be gasified,heated from its cryogenic temperatures to room temperature, andpressurized from low storage pressures to much higher operationpressures. To accomplish this state change, a mechanical pump issometimes used to increase the pressure, accompanied by a heat exchangerto increase the temperature. However, due to the extreme cold and poorlubricity of cryogenic fluid, many mechanical pumps, which utilizerotating components, may not work well. In addition, many mechanicalpumps may suffer from low efficiencies, poor reliability, andcomplexity. Beyond the complexity of the pump, a separate system, suchas a heat exchanger, may need to be utilized to increase the temperatureof the cryogenic fluid. Further, in some existing apparatus, both thepump and the heat exchanger may create a fire hazard by producing liquidair which may be flammable. Still other existing devices may usecryogenic fluid warmed in a large tank, or what is called a batchmethod. This may require excessive weight and size.

An apparatus, and/or method for conditioning cryogenic fluid for use ina device, is needed to decrease one or more problems associated with oneor more of the existing apparatus and/or methods.

SUMMARY

In one aspect of the disclosure, a method is provided for convertingcryogenic fluid for use in a device. In one step, cryogenic fluid isheated to gas using heat transferred from the device to a vessel. Inanother step, temperature and pressure of the gas within the vessel iscontrolled. In still another step, the gas within the vessel istransferred to the device.

In another aspect of the disclosure, an apparatus is provided forfueling a device using cryogenic fluid. The apparatus comprises thefollowing: a cryogenic fluid supply container; a vessel connected to thesupply container with an entrance valve to regulate flow of cryogenicfluid from the supply container to the vessel; a heat transfer systemcapable of transferring heat from a device to the vessel to heat gas inthe vessel; and an accumulator connected to the vessel with an exitvalve to regulate flow of gas from the vessel to the accumulator. Theaccumulator is capable of being connected to a device.

In a further aspect of the disclosure, gas fueling a device is provided.The gas was formed by heating cryogenic fluid in a vessel using heattransferred from the device. The temperature and pressure within thevessel was controlled during formation of the gas. The gas from thevessel was transferred to the device.

These and other features, aspects and advantages of the disclosure willbecome better understood with reference to the following drawings,description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a front view of one embodiment of an apparatus for fuelinga device using hydrogen;

FIG. 2 is a graph showing the pressure and the temperature inside oneembodiment of a vessel when an entrance valve is opened as a function oftime;

FIG. 3 is a graph showing the operating range of density versustemperature for various pressures within one embodiment of a vessel; and

FIG. 4 is a flowchart showing one embodiment of a method for convertinga cryogenic fluid such as hydrogen in a liquid state for use in adevice.

DETAILED DESCRIPTION

The following detailed description is of the best currently contemplatedmodes of carrying out the disclosure. The description is not to be takenin a limiting sense, but is made merely for the purpose of illustratingthe general principles of the disclosure, since the scope of thedisclosure is best defined by the appended claims.

FIG. 1 shows a front view of one embodiment of an apparatus 10 whichsupplies hydrogen fuel 14 to device 12. The device 12 being fueled maycomprise an aircraft, a vehicle, an internal combustion engine, and/oranother type of hydrogen fueled device. The apparatus 10 may comprise athermodynamic pump. The apparatus 10 may include a liquid hydrogensupply container 16, an entrance valve 18, a vessel 20, a firsttemperature sensor 22, a first pressure sensor 24, an exit valve 26, aheat transfer system 28, an accumulator 30, a second temperature sensor32, and a second pressure sensor 34.

The liquid hydrogen supply container 16 may contain hydrogen 14 in aliquid state, and may be connected through one or more pipes 36 to theentrance valve 18 which may be connected to the vessel 20. The vessel 20may comprise a pipe or other type of vessel in which a liquid or gas maybe contained. In one embodiment, the vessel 20 may comprise a 3 footlong pipe having a 2 to 5 inch diameter. In other embodiments, varyingsized vessels 20 may be used depending on the hydrogen demand of thedevice 12. For instance, in one embodiment, two or more vessels 20 maybe used in parallel and manifolded together, and the accumulator 30 maybe replaced by a manifold downstream of exit valve 26.

The entrance valve 18 may be adapted to open to allow hydrogen 14 in aliquid state to be transferred from the supply container 16 into vessel20. The latent heat of vessel 20 may cause the hydrogen 14 supplied fromthe supply container 16 to vaporize and mix with residual warm hydrogengas in vessel 20. Continued contact of the hydrogen in vessel 20 withthe hydrogen at valve 18 may reduce the temperature of the gaseoushydrogen in vessel 20 to near liquid hydrogen temperatures. Once thedesired temperature of the hydrogen in vessel 20 is reached, valve 18may be closed to lock near liquid hydrogen temperature gaseous hydrogenin vessel 20 to be heated using a heat transfer system 28.

The heat transfer system 28 may comprise one or more continuous closedloop pipes which are connected between the vessel 20 and a connecteddevice 12. The heat transfer system 28 may allow heat from the connecteddevice 12, in the form of heated device coolant or in another form, tobe transferred to the vessel 20 in order to heat the hydrogen 14 withinthe vessel 20 to a warm higher pressure gas. The first temperaturesensor 22 and the first pressure sensor 24 may be connected to thevessel 20 in order to monitor the temperature and pressure of thehydrogen 14 within the vessel 20 in both liquid and gaseous states. Thevessel 20 may be connected to the exit valve 26. The exit valve 26 maybe adapted to close to lock hydrogen 14 in a near liquid hydrogentemperature gas state within the vessel 20 so that it can be heated to ahigh pressure warm state, to open to allow hydrogen 14 in a gaseousstate to be transferred to the accumulator 30, and to close to preventmore hydrogen 14 in a gaseous state to enter the accumulator 30. Theexit valve 26 may be connected to the accumulator 30 through one or morepipes 38. The second temperature sensor 32 and the second pressuresensor 34 may be connected to the accumulator 30 in order to monitor thetemperature and pressure of the hydrogen 14 in a gaseous state withinthe accumulator 30. The accumulator 30 may be adapted to store thehydrogen 14 in a gaseous state within the accumulator 30 until thedevice 12 requires hydrogen fueling. The accumulator 30 may be connectedthrough one or more pipes 40 to the device 12 to allow hydrogen 14 in agaseous state to be transferred to the device 12 in order to fuel thedevice 12.

In one embodiment, when the apparatus 10 of FIG. 1 is in operation, theentrance valve 18 may be opened to allow hydrogen 14 in a liquid stateto be transferred from the liquid hydrogen supply container 16 to thevessel 20 while the exit valve 26 is closed. After enough hydrogen 14 ina liquid state is transferred into the vessel 20, the entrance valve 18may be closed. The heat transfer system 28 may then transfer heat fromthe connected device 12 to the vessel 20, in order to heat the hydrogen14 within the vessel 20 from a liquid to a gaseous state. At any time,if the first temperature sensor 22 and/or the first pressure sensor 24detect a temperature and/or pressure within the vessel 20 above a firstset-amount, indicating that the temperature and/or pressure within thevessel 20 is too high, the entrance valve 18 may be opened to allow morehydrogen 14 in a liquid state to be transferred into the vessel 20 tolower the temperature and/or pressure within the vessel 20. In suchmanner, catastrophic failure due to over-pressurization within thevessel 20 may be avoided without having to vent hydrogen 14 in a gaseousstate. The entrance valve 18 may then be closed.

Similarly, if the first temperature sensor 22 and/or the first pressuresensor 24 detect a temperature and/or pressure within the vessel 20above a first set-amount, indicating that the temperature and/orpressure within the vessel 20 is too high, the exit valve 26 may beopened to allow hydrogen 14 in a gaseous state to be transferred fromthe vessel 20 to the accumulator 30 in order to lower the temperatureand/or pressure within the vessel 20. Likewise, when the firsttemperature sensor 22 and/or the first pressure sensor 24 detect atemperature and/or pressure within the vessel 20 which indicates thatthe hydrogen 14 within the vessel is in a suitable gaseous state, theexit valve 26 may be opened to allow the hydrogen 14 in a gaseous stateto be transferred to the accumulator 30.

When enough hydrogen 14 in a gaseous state has been accumulated in theaccumulator 30, the exit valve 26 may be closed. When the secondtemperature sensor 32 and/or the second pressure sensor 34 detect atemperature and/or pressure within the accumulator 30 indicating thatthe hydrogen 14 within the accumulator 30 is in a suitable gaseous stateto fuel the connected device 12, the accumulator 30 may transferhydrogen 14 in a gaseous state to the connected device 12. If the secondtemperature sensor 32 and/or the second pressure sensor 34 detect thatthe temperature and/or pressure within the accumulator 30 is below asecond set-amount, the exit valve 26 may be opened to allow morehydrogen 14, which has been heated within the vessel 20 to a gaseousstate, to be transferred into the accumulator 30 to increase thetemperature and/or pressure of the hydrogen 14 within the accumulator30.

When the vessel 20 needs to be recharged, the entrance valve 18 may beopened to allow hydrogen 14 in a liquid state to be transferred to thevessel 20 from the supply container 16. The pressure within the vessel20 may initially drop which will may allow some of the hydrogen 14 in aliquid form to flow inside the vessel 20. The hydrogen 14 in a liquidform may vaporize as it enters the vessel 20 but at a much lowertemperature than the temperature within the vessel 20. FIG. 2 is a graphshowing the pressure P and the temperature T inside one embodiment ofthe vessel 20 when the entrance valve 18 is opened as a function oftime. The net result may be an increase in density (and increase inmass) inside the vessel 20 showing a net positive mass flow through thevessel 20. The exit valve 26 may then be closed to allow the hydrogen 14within the vessel 20 to be heated to a gaseous state, during which thepressure inside the vessel 20 may rise substantially. In one embodimentwhere the vessel 20 is 3 feet long and 5 inches in diameter, due to thesmall size of the vessel 20, the pressure may exceed 1000 psia. FIG. 3is a graph showing the operating range of density versus temperature forvarious pressures within one embodiment of a vessel 20.

The apparatus 10 of FIG. 1 may not utilize any vents for loweringtemperature and/or pressure of the hydrogen 14 within the vessel 20.This may help to avoid wasting hydrogen 14 as a result of venting.Instead, over pressure and/or temperature protection may be provided bythe ability of the apparatus 10 to depressurize and/or lower thetemperature of the hydrogen 14 within the vessel 20 utilizing thehydrogen 14 within the upstream liquid supply container 16. Moreover,the apparatus 10 may avoid the use of high speed rotational parts.Rather, pressure and/or temperature within the vessel 20 may be achievedutilizing excess heat from the device 12 itself. Rather than utilizing alarge number of movable parts, the only movable parts the apparatus 10may use may be the entrance and exit valves 18 and 26, which may helpreliability and durability. The non-flowing gasification process of theapparatus 10 may result in a stable supply of hydrogen 14 for the device12, as opposed to a typical heat exchanger where the hydrogen may flowthrough the heat exchanger potentially creating an unsteady supply bycausing ice to form in the heating fluid side of the heat exchanger. Theclosed-loop nature of the apparatus 10 may mitigate the risk of liquidair formation within the apparatus 10. The apparatus 10 may be able tohandle a relatively wide range of flow rates and pressures toaccommodate for the hydrogen requirements of the device 12.

FIG. 4 is a flowchart showing one embodiment of a method 242 forconverting hydrogen 14 in a liquid state for use in a device 12. Thedevice 12 may comprise an internal combustion engine, an aircraft, avehicle, or other type of device. In one step 244, hydrogen 14 in aliquid state in a vessel 20 may be heated to a gaseous state using heattransferred from the device 12. In one embodiment, a size of the vessel20 may be determined based on the requirements of the device 12. Inanother step 246, temperature and pressure of the hydrogen 14 within thevessel 20 may be controlled. In one embodiment, a first temperaturesensor 22 and a first pressure sensor 24 may be used to control thetemperature and pressure of the hydrogen 14 within the vessel 20. Inanother embodiment, hydrogen 14 in a liquid state may be transferredfrom a supply container 16 to the vessel 20 when at least one of thetemperature and pressure of the hydrogen 14 within the vessel 20 is overa first set-amount. The method 242 may not utilize any vents to lower atleast of the temperature and pressure of the hydrogen 14 within thevessel 20. In another embodiment, hydrogen 14 in the vessel 20 may beheated using heat transferred from the device 12 when at least one ofthe temperature and pressure of the hydrogen 14 within the vessel 20 isunder a third set-amount. In still another step 248, hydrogen 14 in agaseous state within the vessel 20 may be transferred to the device 12.In one embodiment, hydrogen 14 in a gaseous state within the vessel 20may be first transferred to an accumulator 30, and then transferred tothe device 12.

In another embodiment, additional steps of the method 242 may compriseproviding a supply container 16, and transferring hydrogen 14 in aliquid state from the supply container to the vessel 20. Still othersteps may comprise providing an entrance valve 18 to the vessel 20,providing an exit valve 26 to the vessel 20, and heating the hydrogen 14in a liquid state within the vessel 20 to a gaseous state while both ofthe entrance and exit valves 18 and 26 are closed. The entrance valve 18may be connected to a liquid hydrogen supply container 16, and the exitvalve 26 may be connected to an accumulator 30 which may be connected tothe device 12. In yet another embodiment, an additional step of themethod 242 may comprise controlling the temperature and pressure ofhydrogen 14 in a gaseous state within the accumulator 30. A secondtemperature sensor 32 and a second pressure sensor 34 may be used tocontrol the temperature and pressure of hydrogen 14 in a gaseous statewithin the accumulator 30. When at least of the temperature and pressureof the hydrogen 14 in a gaseous state within the accumulator 30 is undera second set-amount, additional hydrogen 14 in a gaseous state may betransferred from the vessel 20 to the accumulator 30.

In an additional embodiment, hydrogen 14 fueling a device 12, while in agaseous state, may be provided. The hydrogen 14 in the gaseous state mayhave been formed by heating hydrogen 14 in a liquid state in a vessel 20to a gaseous state using heat transferred from the device 12. Thetemperature and pressure within the vessel 20 may have been controlledduring formation of the hydrogen 14 into the gaseous state. The hydrogen14 in the gaseous state may have been transferred to the device 12. Thedevice 12 being fueled may be at least one of an internal combustionengine, an aircraft, a vehicle and another type of fueled device.

Although the above embodiments are directed towards using hydrogen 14 tofuel the device 12, all of the embodiments of the disclosure are equallyapplicable to using another type of cryogenic fluid rather thanhydrogen, such as nitrous oxide, methane, or other type of very lowtemperature or substantially low temperature fluid to fuel the device12.

One or more embodiments of the disclosure may reduce and/or eliminateone or more problems of one or more of the existing apparatus and/ormethods. For instance, one or more embodiments of the apparatus and/ormethod of the disclosure may reduce the need for high speed rotationalparts, reduce the need for moving parts other than valves, reducehydrogen waste due to venting, provide a more stable supply of hydrogen,help in mitigating the risk of liquid air formation, more easily handlea wide range of flow rates and pressures depending on the hydrogenrequirements, increase durability, increase reliability, take up lessspace, take up less weight, be less costly, decrease hydrogen loss, bemore stable, accommodate a wide range of devices, mitigate liquid airformation, be more efficient, be easier to implement, and/or may reduceone or more other types of problems with one or more of the existingapparatus and/or methods.

It should be understood, of course, that the foregoing relates toexemplary embodiments of the disclosure and that modifications may bemade without departing from the spirit and scope of the disclosure asset forth in the following claims.

The invention claimed is:
 1. An apparatus for fueling a device usingcryogenic fluid comprising: a cryogenic fluid supply containerconfigured to supply a cryogenic fluid; a vessel connected to thecryogenic fluid supply container with an entrance valve configured toregulate flow of the cryogenic fluid from the cryogenic fluid supplycontainer into the vessel; a device; a heat transfer system configuredto transfer heat, while the vessel is being supplied with the cryogenicfluid from the cryogenic fluid supply container, from the device to thevessel to vaporize the cryogenic fluid in the vessel, supplied by thecryogenic fluid supply container, into the cryogenic gas; an exit valveconfigured to regulate flow of the cryogenic gas from the vessel to fuelthe device with the cryogenic gas, wherein the cryogenic fluid and thecryogenic gas are not vented to atmosphere or to the cryogenic fluidsupply container; and a control system controlling the entrance valve,the control system programmed so that when a temperature or a pressureof the cryogenic gas within the vessel is over a set-amount, caused bythe heat transfer system, the control system opens the entrance valve totransfer more cryogenic fluid from the cryogenic fluid supply containerinto the vessel.
 2. The apparatus of claim 1 wherein the devicecomprises an aircraft, a vehicle, or an internal combustion engine. 3.The apparatus of claim 1 wherein the vessel is connected to a pressuresensor and to a temperature sensor which are configured to monitor thepressure and the temperature within the vessel.
 4. The apparatus ofclaim 1 wherein the heat transfer system comprises at least one pipemember.
 5. The apparatus of claim 1 further comprising an accumulatorconnected to the exit valve and to the device, wherein the accumulatoris connected to a pressure sensor and to a temperature sensor which areconfigured to monitor the pressure and the temperature within theaccumulator.
 6. The apparatus of claim 5 wherein the control system isprogrammed to open the exit valve when the temperature or the pressurewithin the accumulator is below the set-amount.
 7. The apparatus ofclaim 1 wherein the control system is programmed to close both theentrance and exit valves during transfer of the heat from the device tothe vessel to vaporize the cryogenic fluid in the vessel into thecryogenic gas.
 8. An apparatus for fueling a device using cryogenicfluid comprising: a cryogenic fluid supply container configured tosupply a cryogenic fluid; a vessel connected to the cryogenic fluidsupply container with an entrance valve configured to regulate flow ofthe cryogenic fluid from the cryogenic fluid supply container into thevessel; a device; a heat transfer system configured to transfer heat,while the vessel is being supplied with the cryogenic fluid from thecryogenic fluid supply container, from the device to the vessel tovaporize the cryogenic fluid in the vessel, supplied by the cryogenicfluid supply container, into the cryogenic gas; an accumulator connectedto the vessel with an exit valve configured to regulate flow of thecryogenic gas from the vessel into the accumulator to fuel the devicewith the cryogenic gas, wherein the cryogenic fluid and the cryogenicgas are not vented to atmosphere or to the cryogenic fluid supplycontainer; and a control system controlling the entrance valve, thecontrol system programmed so that when a temperature or a pressure ofthe cryogenic gas within the vessel is over a set-amount, caused by theheat transfer system, the control system opens the entrance valve totransfer more cryogenic fluid from the cryogenic fluid supply containerinto the vessel.
 9. The apparatus of claim 8 wherein the devicecomprises an aircraft, a vehicle, or an internal combustion engine. 10.The apparatus of claim 8 wherein the vessel is connected to a pressuresensor and to a temperature sensor which are configured to monitor thepressure and the temperature within the vessel.
 11. The apparatus ofclaim 8 wherein the heat transfer system comprises at least one pipemember.
 12. The apparatus of claim 8 wherein the accumulator isconnected to a pressure sensor and to a temperature sensor which areconfigured to monitor the pressure and the temperature within theaccumulator.
 13. The apparatus of claim 8 wherein the control system isprogrammed to open the exit valve when the temperature or the pressurewithin the accumulator is below the set-amount.
 14. The apparatus ofclaim 8 wherein the control system is programmed to close both theentrance and exit valves during transfer of the heat from the device tothe vessel to vaporize the cryogenic fluid in the vessel into thecryogenic gas.
 15. An apparatus for fueling a device using cryogenicfluid comprising: a cryogenic fluid supply container configured tosupply a cryogenic fluid; a vessel connected to the cryogenic fluidsupply container with an entrance device configured to regulate flow ofthe cryogenic fluid from the cryogenic fluid supply container into thevessel; a device; a heat transfer system configured to transfer heat,while the vessel is being supplied with the cryogenic fluid from thecryogenic fluid supply container, from the device to the vessel tovaporize the cryogenic fluid in the vessel, supplied by the cryogenicfluid supply container, into the cryogenic gas; an exit deviceconfigured to regulate flow of the cryogenic gas from the vessel to fuelthe device with the cryogenic gas, wherein the cryogenic fluid and thecryogenic gas are not vented to atmosphere or to the cryogenic fluidsupply container; and a control system controlling the entrance device,the control system programmed so that when a temperature or a pressureof the cryogenic gas within the vessel is over a set-amount, caused bythe heat transfer system, the control system opens the entrance deviceto transfer more cryogenic fluid from the cryogenic fluid supplycontainer into the vessel.
 16. The apparatus of claim 15 wherein theentrance device comprises an entrance valve.
 17. The apparatus of claim15 wherein the exit device comprises an exit valve.
 18. The apparatus ofclaim 15 wherein the device comprises an aircraft, a vehicle, or aninternal combustion engine.